Marine debris collection device

ABSTRACT

A marine debris collection device includes an outer container, an inner container provided inside the outer container so as to be movable in an upward-downward direction with respect to the outer container, a pump to move the inner container downward and cause seawater and debris to flow into the inner container via an opening, and a lower buoyant body detachably attached to a lower portion of the inner container to maintain the opening of the inner container above a water surface when the pump is not driven.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese Patent Application No. 2021-051758 filed on Mar. 25, 2021 and Japanese Patent Application No. 2021-093535 filed on Jun. 3, 2021. The entire contents of these applications are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a marine debris collection device, and more particularly, it relates to a marine debris collection device that collects debris floating on the sea by allowing the debris to flow together with seawater into the marine debris collection device.

2. Description of the Related Art

In recent years, from the perspective of protecting the marine environment toward sustainable development goals (so-called SDGs), activities have been promoted to protect the richness of the sea by collecting and reducing garbage and microplastics floating on the water. A marine debris collection device that collects debris floating on the sea by allowing the debris to flow together with seawater into the marine debris collection device is known in general, for example. Such a marine debris collection device is disclosed in Japanese Translation of PCT International Application Publication No. 2020-500709, for example.

Japanese Translation of PCT International Application Publication No. 2020-500709 discloses a waste collection device including a container (outer container) installed in the vicinity of or adjacent to the water surface, a tubular member (inner container) including an opening that allows seawater and debris to flow into the tubular member at an upper portion of the tubular member, provided inside the container so as to be movable in an upward-downward direction with respect to the container, and storing the debris that flows into the tubular member via the opening, and a pump. The waste collection device collects marine debris and preserves the environment. An annular chamber that provides buoyancy to the tubular member (inner container) is provided inside the tubular member (inner container). Thus, the tubular member (inner container) itself is a buoyant body. When the pump is not driven, the opening of the tubular member (inner container) is maintained at a position above the water surface by the buoyancy of the annular chamber. When the pump is driven, the tubular member (inner container) moves downward, and the opening is held at a height equal to or lower than the height of the water surface. Consequently, the waste collection device allows seawater and debris in the vicinity of or adjacent to the water surface to flow into the tubular member (inner container) via the opening.

In the waste collection device disclosed in Japanese Translation of PCT International Application Publication No. 2020-500709, the tubular member (inner container) itself provided inside the container (outer container) is a buoyant body. Therefore, when the buoyancy of the tubular member (inner container) is set according to the water quality of an area of the sea in which the waste collection device is used, for example, it is necessary to change the shape itself of the tubular member (inner container), and it takes time and effort. Therefore, conventionally, it has been desired to facilitate the setting of the buoyancy of the tubular member (inner container).

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide marine debris collection devices that facilitate setting of the buoyancies of inner containers.

A marine debris collection device according to a preferred embodiment of the present invention collects debris floating on a sea by allowing the debris to flow together with seawater into the marine debris collection device, and includes an outer container installed in a vicinity of or adjacent to a water surface to maintain a height of the outer container, an inner container including, in an upper portion thereof, an opening to allow the seawater and the debris to flow into the inner container, the inner container being provided inside the outer container so as to be movable in an upward-downward direction with respect to the outer container to store the debris that flows into the inner container via the opening, a pump driven to move the inner container downward such that the opening is located at a height equal to or lower than a height of the water surface and cause the seawater and the debris to flow into the inner container via the opening, and a lower buoyant body detachably attached to a lower portion of the inner container to provide buoyancy to the inner container so as to maintain the opening above the water surface when the pump is not driven.

A marine debris collection device according to a preferred embodiment of the present invention includes the lower buoyant body detachably attached to the lower portion of the inner container that is movable in the upward-downward direction with respect to the outer container to provide buoyancy to the inner container and maintain the opening above the water surface when the pump is not driven. Accordingly, unlike the conventional structure in which the buoyancy of the inner container is determined by the shape of the inner container itself, which is a buoyant body, the buoyancy of the inner container is determined by the lower buoyant body that is separate from the inner container and detachably attached to the lower portion of the inner container. Therefore, the buoyancy of the inner container is set by detaching and replacing the lower buoyant body with another lower buoyant body having a different buoyancy, for example, without changing the shape of the inner container itself. Therefore, the buoyancy of the inner container is easily set by the lower buoyant body attachable to and detachable from the inner container. Thus, the marine debris collection device facilitates setting of the buoyancy of the inner container, and thus the buoyancy of the inner container is easily set to preferred buoyancies depending on areas of the sea having various water qualities around the world. Therefore, the marine debris collection device is used to collect the debris on the sea and contribute to environmental conservation in areas of the sea having various water qualities around the world.

In a marine debris collection device according to a preferred embodiment of the present invention, the lower buoyant body preferably includes a plurality of lower buoyant bodies detachably attached to a lower surface of the inner container. Accordingly, as compared with a case in which one lower buoyant body is attached, the overall buoyancy is easily fine-tuned by using the plurality of lower buoyancy bodies.

In such a case, the inner container preferably includes a water passage to allow the seawater to pass therethrough, and the plurality of lower buoyant bodies preferably surround the water passage. Accordingly, the lower buoyant bodies are attached to the lower surface of the inner container without obstructing the flow of the seawater through the water passage.

In a marine debris collection device including the plurality of lower buoyant bodies that surround the water passage, the lower surface of the inner container preferably has an annular shape to surround the water passage, and each of the plurality of lower buoyant bodies preferably includes an inner peripheral surface and an outer peripheral surface each having an arcuate shape to extend along the lower surface and having a plate shape with the upward-downward direction corresponding to a thickness direction of the plate shape. Accordingly, the lower buoyant body each has a shape along the lower surface of the inner container, and thus a resistance of the lower buoyant bodies to movement of the inner container is significantly reduced or prevented when the inner container moves in the upward-downward direction.

A marine debris collection device according to a preferred embodiment of the present invention preferably further includes a stopper attached to the inner container to restrict upward movement of the inner container at a predetermined height by contacting the outer container, and the lower buoyant body is preferably detachably attached to a lower surface of the inner container together with the stopper. Accordingly, the lower buoyant body and the stopper are attached together to the lower surface of the inner container, and thus as compared with a case in which the lower buoyant body and the stopper are attached to the lower surface of the inner container by different structures, the device structure is simplified.

In such a case, a marine debris collection device according to a preferred embodiment of the present invention preferably further includes a fastener to detachably fix the lower buoyant body together with the stopper to the lower surface of the inner container. Accordingly, the lower buoyant body and the stopper are easily attached to and detached from the inner container by the fastener.

In a marine debris collection device according to a preferred embodiment of the present invention, the inner container preferably includes an upper surface including an annular flat portion that includes a horizontal or substantially horizontal surface and extends along the opening to surround the opening, and an annular protrusion that surrounds the flat portion, protrudes upward from the flat portion, and is connected to an outer peripheral edge of the flat portion from above. Accordingly, the seawater and debris in the vicinity of or adjacent to the water surface that have passed over the protrusion contact the flat portion such that the flow from the upper side to the lower side is directed inward horizontally, and obliquely upward and inward (i.e., the seawater is caused to jump or splash obliquely upward and inward) in front of the opening. Consequently, a strong flow toward the vicinity of the center of the opening as a whole is generated inside the inner container, and thus the seawater and debris are efficiently taken into the inner container.

In such a case, the protrusion preferably has an arcuate shape that protrudes upward in a direction perpendicular to a direction in which the protrusion annularly extends. Accordingly, the protrusion has an arcuate shape, and thus the seawater and debris easily pass over the protrusion and flow into the inner container.

In a marine debris collection device including the inner container including the upper surface that includes the flat portion and the protrusion, the inner container preferably includes a cylindrical inner container body, and a mesh container detachably installed inside the inner container body to store the debris and including an upper end located below the flat portion when the mesh container is installed inside the inner container body, and the flat portion of the inner container preferably guides, inward of the mesh container, the seawater and the debris that flow over the protrusion into the inner container by contacting the inflowing seawater and debris and directing a flow of the inflowing seawater and debris obliquely upward and inward. Accordingly, the flow of the seawater and debris that flow over the protrusion into the inner container is directed obliquely upward and inward by the flat portion such that the seawater and debris are guided to a location farther away from the upper end of the mesh container. Consequently, clogging of a space between the mesh container and the inner container body due to the flow of the debris into between the mesh container and the inner container body is significantly reduced or prevented.

In a marine debris collection device including the inner container including the upper surface that includes the protrusion, the protrusion is preferably internally recessed upward such that a lower side of the protrusion is open and preferably includes an outer surface including a through-hole, and when the seawater flows into the inner container, internal air is preferably drawn via the through-hole into the seawater that flows into the inner container, and the seawater preferably flows into the protrusion from the open lower side. Accordingly, the air inside the protrusion is allowed to flow into the inner container via the through-hole by the flow of the seawater, and the seawater is allowed to flow into the protrusion from the open lower side of the protrusion. Thus, the inner container is submerged such that the position of the protrusion with respect to the water surface is lower. Consequently, the protrusion is located at a lower position with respect to the water surface, and thus the flow of the seawater that flows into the inner container is further increased, and the debris is effectively attracted.

A marine debris collection device according to a preferred embodiment of the present invention preferably further includes a slider provided between the outer container and the inner container to smooth the movement of the inner container with respect to the outer container. Accordingly, when the inner container moves in the upward-downward direction, the slider reduces a resistance between the inner container and the outer container.

A marine debris collection device according to a preferred embodiment of the present invention preferably further includes an upper buoyant body that is provided on the upper portion of the inner container to provide buoyancy to the inner container, is located below the water surface when the pump is driven, and maintains the opening above the water surface when the pump is not driven. Accordingly, when the pump is driven, the buoyancy of the upper buoyant body is generated only when the upper portion of the inner container is located below the water surface, and thus the upper portion of the inner container is held below the water surface and in the vicinity of or adjacent to the water surface. Consequently, the flow of not only the seawater and debris in the vicinity of or adjacent to the water surface but also seawater below in the vicinity of or adjacent to the water surface into the inner container due to excessive movement of the upper portion of the inner container below the water surface is significantly reduced or prevented.

In such a case, the inner container preferably includes an annular flat portion that includes a horizontal or substantially horizontal surface and extends along the opening to surround the opening, and a sealed, hollow, and annular protrusion that surrounds the flat portion, protrudes upward from the flat portion, and is connected to an outer peripheral edge of the flat portion from above, and the upper buoyant body preferably includes a sealed, hollow, and annular portion of the protrusion. Accordingly, the shape of the upper buoyant body is determined by the shape of the sealed, hollow, and annular portion of the protrusion of the inner container, and thus the device structure is simplified.

In a marine debris collection device according to a preferred embodiment of the present invention, the pump is preferably directly attached to a lower surface of the outer container from an outside of the outer container. Accordingly, the pump is provided outside the outer container, and thus it is not necessary to provide a space to provide the pump inside the outer container, and the outer container is downsized.

In a marine debris collection device according to a preferred embodiment of the present invention, the pump preferably includes a pump body, and a branch discharge pipe to divide the seawater discharged from the pump body into a plurality of branches and discharge the seawater in a plurality of horizontal directions different from each other. Accordingly, the seawater discharged from the pump is divided into a plurality of small flows and discharged by the branch discharge pipe, and thus disturbance of the flow of the seawater in the vicinity of or adjacent to the water surface due to the flow of the seawater discharged from the pump is significantly reduced or prevented. Furthermore, the branch discharge pipe cancels a reaction force received by the pump (marine debris collection device) from the flow of the seawater discharged from the pump.

In a marine debris collection device according to a preferred embodiment of the present invention, the lower buoyant body is preferably solid. Accordingly, the solid lower buoyant body facilitates the setting of the buoyancy of the inner container.

A marine debris collection device according to a preferred embodiment of the present invention preferably further includes a bracket to fix the outer container to a pier. Accordingly, the outer container is easily fixed to the pier by the bracket.

In a marine debris collection device according to a preferred embodiment of the present invention, the pump preferably includes a suction port provided directly below a central or substantially central portion of a bottom surface of the inner container, and the inner container preferably includes a water-impermeable portion provided on the bottom surface directly above the suction port to prevent the seawater from passing therethrough, and a bottom water passage provided on the bottom surface around the water-impermeable portion to allow the seawater to pass therethrough. Accordingly, the water-impermeable portion significantly reduces or prevents the possibility that air directly enters the pump, and thus the seawater is allowed to more efficiently flow into the pump. Consequently, the efficiency of water discharge of the pump is improved.

In a marine debris collection device according to a preferred embodiment of the present invention, the inner container preferably includes a water passage to allow the seawater to pass therethrough, and the water passage preferably includes a bottom water passage provided on a bottom surface of the inner container, and a side water passage provided on a side surface of the inner container. Accordingly, the debris gradually accumulates from below inside the inner container, and thus even when the bottom water passage in which the debris is likely to accumulate (i.e., that is likely to be clogged with the debris) is clogged, the debris is continuously collected by the side water passage in which the debris is unlikely to accumulate (i.e., that is unlikely to be clogged with the debris). Consequently, the marine debris collection device continues to collect the debris for a relatively long time. Therefore, the maintenance interval to remove the debris from the marine debris collection device is lengthened.

In a marine debris collection device according to a preferred embodiment of the present invention, the pump preferably includes a pump body, and an outer discharge pipe including a discharge port provided outside an outer peripheral surface of the outer container in a horizontal direction to discharge the seawater discharged from the pump body to an outside of the pump via the discharge port. Accordingly, the outer discharge pipe discharges the seawater and air (air bubbles) contained in the seawater into the sea at a location relatively far from the outer container, and thus generation of air bubbles in the vicinity of or adjacent to the outer container is significantly reduced or prevented. Consequently, obstruction of flowing of the debris into the inner container due to generated air bubbles is significantly reduced or prevented.

The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing the state of a marine debris collection device according to a first preferred embodiment of the present invention when a pump is not driven.

FIG. 2 is a perspective view showing an inner container, stoppers, and lower buoyant bodies of the marine debris collection device according to the first preferred embodiment of the present invention.

FIG. 3 is a sectional view showing the state of the marine debris collection device according to the first preferred embodiment of the present invention when the pump is driven.

FIG. 4 is a view taken along the line IV-IV in FIG. 3.

FIG. 5 is a partially enlarged view of a portion A in FIG. 3.

FIG. 6 is a perspective view showing a marine debris collection device according to a second preferred embodiment of the present invention.

FIG. 7 is a sectional view showing the marine debris collection device according to the second preferred embodiment of the present invention installed on a pier.

FIG. 8 is an enlarged sectional view showing a state in which seawater flows into an inner container according to the second preferred embodiment of the present invention.

FIG. 9 is an enlarged perspective view showing a lower portion of an inner container body according to the second preferred embodiment of the present invention from the lower side.

FIG. 10 is a perspective view showing the inner container and an outer container according to the second preferred embodiment of the present invention from the upper side.

FIG. 11 is a diagram showing the marine debris collection device according to the second preferred embodiment of the present invention that is being moved on land.

FIG. 12 is a perspective view illustrating attachment of a marine debris collection device body according to the second preferred embodiment of the present invention to the pier with a bracket.

FIG. 13 is a diagram showing the marine debris collection device body according to the second preferred embodiment of the present invention that is being moved between land and water.

FIG. 14 is a perspective view showing an inner container, a stopper, and a lower buoyant body of a marine debris collection device according to a modified example and showing a structure corresponding to FIG. 2.

FIG. 15 is a sectional view showing a protrusion of an inner container according to a first modified example and showing a structure corresponding to FIG. 5.

FIG. 16 is a sectional view showing a protrusion of an inner container according to a second modified example and showing a structure corresponding to FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are hereinafter described with reference to the drawings.

First Preferred Embodiment

The structure of a marine debris collection device 100 according to a first preferred embodiment of the present invention is now described with reference to FIGS. 1 to 5.

The marine debris collection device 100 is installed in the vicinity of or adjacent to the water surface. The marine debris collection device 100 collects debris G floating on the sea by allowing the debris G to flow together with seawater into the marine debris collection device 100 with a pump 3 and storing the debris G in a mesh container 51. The marine debris collection device 100 collects relatively large debris such as PET bottles and fallen leaves and even minute debris. The marine debris collection device 100 removes the debris G on the sea and preserves the environment.

As shown in FIG. 1, the marine debris collection device 100 includes an outer container 1, a bracket 2, the pump 3, sliders 4 a, seals 4 b, an inner container 5 including an inner container body 50 and a mesh container 51, stoppers 6, lower buoyant bodies 7, fasteners B (see FIG. 2), and an upper buoyant body 9.

The pump 3, the sliders 4 a, and the seals 4 b are attached to the outer container 1. The inner container 5 is provided inside the outer container 1 so as to be movable in an upward-downward direction with respect to the outer container 1.

The stoppers 6 and the lower buoyant bodies 7 are attached to the inner container 5 by the fasteners B. The upper buoyant body 9 is provided on the inner container 5. Thus, the stoppers 6, the lower buoyant bodies 7, the fasteners B, and the upper buoyant body 9 move together with the inner container 5 in the upward-downward direction. In each figure, the upward-downward direction is defined as a Z direction, an upward direction is defined as a Z1 direction, and a downward direction is defined as a Z2 direction.

The outer container 1 is fixed to a pier F floating on the water surface by the bracket 2. Thus, the outer container 1 is installed in the vicinity of or adjacent to the water surface to maintain its height with respect to the water surface. The upper surface 13 of the outer container 1 is constantly located below the water surface. Furthermore, the outer container 1 is installed at a predetermined height such that the inner container 5 is located on the water surface when the inner container 5 moves up and down. As an example, the outer container 1 is made of fiber reinforced plastics (FRP).

The outer container 1 is a cylindrical hollow container including an opening 1 a at its upper end. The outer container 1 includes an air chamber 10 in its inner upper portion and a pump connection hole 11 in the center of its lower surface 12.

The air chamber 10 has a cylindrical shape to extend along the inner peripheral surface of the annular outer container 1. The air chamber 10 includes, at its lower end, a lower hole 10 a that communicates with the internal space of the outer container 1. The air chamber 10 is constantly filled with air regardless of the driving state of the pump 3. The air chamber 10 has a negative pressure when the pump 3 is driven and a positive pressure when the pump 3 is not driven.

The bracket 2 fixes the outer container 1 to the pier F at a predetermined height. The bracket 2 may adjust the height of the outer container 1 with respect to the pier F. The bracket 2 includes a support 20 to support the outer container 1 and a rod 21 that extends linearly in the upward-downward direction. An upper portion of the rod 21 is fixed to the pier F, and a lower portion thereof holds the support 20.

The pump 3 is a submersible electric pump to drive an impeller 30 b with an electric motor 30 a, for example. The pump 3 takes in seawater from the inside of the outer container 1 and discharges the seawater to the outside of the outer container 1 by driving the impeller 30 b in a pump chamber.

The pump 3 includes a pump body 30 including the electric motor 30 a and the impeller 30 b, and a branch discharge pipe 31 attached to the pump body 30.

The pump body 30 (pump 3) is directly attached to the lower surface 12 of the outer container 1 from the outside of the outer container 1. The pump body 30 (pump 3) takes in seawater from the inside of the outer container 1 through the pump connection hole 11 of the outer container 1. The pump body (pump 3) is provided in a central or substantially central portion (hereinafter “substantially central portion”) of the annular outer container 1 in a horizontal direction.

The pump body 30 (pump 3) is provided outside the outer container 1 and directly below the inner container 5. Specifically, the pump body 30 (pump 3) is provided directly below a water passage 53 described below in the inner container 5.

The branch discharge pipe 31 has a T shape (see FIG. 4). The branch discharge pipe 31 divides the seawater discharged from the pump body 30 (pump chamber) into a plurality of (two) branches and discharges the seawater in a plurality of (two) horizontal directions different from each other. Specifically, the branch discharge pipe 31 discharges the seawater discharged from the pump body 30 (pump chamber) in two predetermined directions opposite to each other in the horizontal direction.

As shown in FIG. 3, the pump 3 is driven to move (attract or pull) the inner container 5 downward such that an opening 5 a described below of the inner container 5 is located at a height equal to or lower than the height of the water surface and allow the seawater and debris G to flow into the inner container 5 via the opening 5 a.

A plurality of sliders 4 a are attached to the inner peripheral surface of a casing of the outer container 1 that defines the air chamber 10. Therefore, the sliders 4 a are located between the outer container 1 and the inner container 5 (the inner container body 50 described below). Thus, the sliders 4 a are provided between the outer container 1 and the inner container 5 in the radial direction of the cylindrical outer container 1.

The sliders 4 a are directly fixed to the outer container 1 by fasteners (not shown) such as bolts. The sliders 4 a are attached to the outer container 1 to not move in the upward-downward direction together with the inner container 5.

The sliders 4 a are rectangular plate-shaped members curved along the inner peripheral surface of the cylindrical outer container 1. The plurality of sliders 4 a are provided at equal or substantially equal angular intervals in the circumferential direction of the cylindrical outer container 1.

The sliders 4 a have a function of smoothing the movement of the inner container 5 with respect to the outer container 1. As an example, the sliders 4 a are made of a material having excellent sliding properties such as Duracon (registered trademark) or Teflon (registered trademark).

The seals 4 b include elastic annular members. A plurality of (two) seals 4 b are attached to the inner peripheral surface of the casing of the outer container 1 that defines the air chamber 10. Specifically, the seals 4 b are provided between the outer container 1 and the inner container 5 (the inner container body 50 described below), and one of the seals 4 b is provided above the sliders 4 a while the other is provided below the sliders 4 a.

That is, the two seals 4 b are provided between the outer container 1 and the inner container 5 in the radial direction of the cylindrical outer container 1, and the sliders 4 a are provided between the two seals 4 b in the upward-downward direction. The seals 4 b are attached to the outer container 1 so as to not move together with the inner container 5 in the upward-downward direction.

The seals 4 b prevent water from entering (a gap) between the outer container 1 and the inner container 5. The seals 4 b cause seawater to flow into the inner container 5 and the outer container 1 only via the opening 5 a when the marine debris collection device 100 allows the debris G floating on the sea to flow together with the seawater thereinto via the opening 5 a described below of the inner container 5.

That is, the marine debris collection device 100 moves (attracts or pulls) the inner container 5 downward by driving the pump 3 and allows seawater to flow into the inner container 5 and the outer container 1 via the opening 5 a only when the opening 5 a is located at a height equal to or lower than the height of the water surface. As an example, the seals 4 b are mohair seals.

The inner container 5 is provided inside the outer container 1 so as to be movable in the upward-downward direction with respect to the outer container 1.

The lower buoyant bodies 7 that provide buoyancy to the inner container 5 are attached to the inner container 5. Furthermore, the upper buoyant body 9 that provides buoyancy to the inner container 5 is provided on the inner container 5.

The inner container 5 is a cylindrical hollow container including the opening 5 a at its upper end (upper portion) to allow the seawater and debris G to flow into the inner container 5. The inner container 5 stores the debris G that flows thereinto via the opening 5 a. The opening 5 a of the inner container 5 is held at a height equal to or lower than the height of the water surface when the pump 3 is driven, and is held at a height above the water surface when the pump 3 is not driven.

The inner container 5 includes the cylindrical inner container body 50 and the mesh container 51 detachably installed inside the inner container body 50 to store the debris G.

The opening 5 a is provided at the upper end of the inner container body 50. The inner container body 50 has a cylindrical shape. The inner container body 50 (inner container 5) includes, at its lower end, an annular portion 52 and the circular water passage 53 provided inside the annular portion 52. Thus, the lower surface 54 of the inner container 5 has an annular shape to surround the water passage 53. As an example, the inner container body 50 is made of FRP or high-density polyethylene (HDPE).

The mesh container 51 is a cylindrical hollow container including an opening on the upper side and having a mesh shape. The mesh container 51 allows only seawater to pass therethrough toward the water passage 53 (pump 3), filters the debris G, and stores the debris G therein when the debris G floating on the sea is allowed to flow together with the seawater into the mesh container 51 via the opening 5 a of the inner container 5.

The mesh container 51 is installed inside the inner container body 50. The mesh container 51 is detachable from the inner container body 50. The upper end 51 a of the mesh container 51 is located below a flat portion 55 a and a protrusion 55 b described below on the upper surface 55 of the inner container 5 (inner container body 50) while the mesh container 51 is installed inside the inner container body 50.

As shown in FIG. 1, the mesh container 51 includes a removable handle 51 b. The handle 51 b is removed from the mesh container 51 during normal use of the marine debris collection device 100, i.e., when the marine debris collection device 100 allows the debris G floating on the sea to flow thereinto together with seawater. Therefore, catching of the debris G on the handle 51 b is prevented.

The handle 51 b is attached to the mesh container 51 when the stored debris G is removed from the inside of the mesh container 51. Then, the mesh container 51 is lifted upward by a user who grips the handle 51 b, and is removed from the inner container body 50.

When the pump 3 is not driven, the inner container 5 is floated by the lower buoyant bodies 7 (and the upper buoyant body 9) such that the upper surface 55 of the inner container 5 is held above the water surface (at a position that does not contact seawater). On the other hand, when the pump 3 is driven, the upper surface 55 of the inner container 5 is moved (attracted) downward by the pump 3 to be held at a height equal to or lower than the height of the water surface (a position that contacts seawater).

As shown in FIGS. 3 and 5, the upper surface 55 of the inner container 5 includes the annular flat portion 55 a and the annular protrusion 55 b.

The flat portion 55 a includes a horizontal or substantially horizontal surface (hereinafter, “substantially horizontal surface”) and extends along the opening 5 a to surround the opening 5 a of the inner container 5. The flat portion 55 a is located below the water surface when the debris G floating on the sea is allowed to flow together with seawater into the inner container 5 via the opening 5 a of the inner container 5. At this time, the protrusion 55 b is located at a height equal to or lower than the height of the water surface and at substantially the same height as that of the water surface.

The protrusion 55 b surrounds the flat portion 55 a and protrudes upward from the flat portion 55 a. The protrusion 55 b is connected to the outer peripheral edge 55 c (see FIG. 5) of the flat portion 55 a from above. The protrusion 55 b has an arcuate shape (semicircular shape) that protrudes upward in a direction perpendicular to a direction in which the protrusion 55 b annularly extends.

The flat portion 55 a guides the seawater and debris G that flow over the protrusion 55 b into the inner container 5 inward of the mesh container 51 by contacting the inflowing seawater and debris G and directing the flow of the inflowing seawater and debris G obliquely upward and inward.

In short, the flat portion 55 a causes the seawater and debris G that flow over the protrusion 55 b into the inner container 5 to jump or splash by contacting the inflowing seawater and debris G such that a space between the mesh container 51 and the inner container body 50 is not clogged with the debris G, and guides the inflowing seawater and debris G to a location away from the upper end 51 a of the mesh container 51. The flow of the seawater that has jumped in the flat portion 55 a has a preferable design aspect that evokes the aesthetics when visually recognized from above.

As shown in FIG. 2, a plurality of (three, for example) stoppers 6 are detachably attached to the lower surface (annular portion 52) of the inner container 5. The stoppers 6 protrude outward in the horizontal direction from a position that overlaps the lower surface 54 of the inner container 5. The stoppers 6 preferably have the same shapes as those of the lower buoyant bodies 7 as viewed in the upward-downward direction.

Specifically, the stoppers 6 each have a shape defined by two large and small arcs and two straight lines connecting the two arcs as viewed in the upward-downward direction. The plurality of stoppers 6 are preferably provided at equal angular intervals in the circumferential direction of the annular lower surface 54 of the inner container 5. As an example, the stoppers 6 are made of Duracon.

The stoppers 6 restrict upward movement of the inner container 5 at a predetermined height by contacting the outer container 1 (see FIG. 1) when the inner container 5 moves upward. Specifically, when the inner container 5 moves upward, the stoppers 6 contact the casing of the outer container 1 that defines the air chamber 10 from below to restrict upward movement of the inner container 5 at the predetermined height.

In short, the stoppers 6 define an uppermost position in the movement range of the inner container 5 in the upward-downward direction. The stoppers 6 prevent the inner container 5 from moving too far upward and being detached from the outer container 1.

As shown in FIGS. 1 and 2, the lower buoyant bodies 7 are detachably attached to a lower portion (lower surface 54) of the inner container 5 and provide buoyancy to the inner container 5. The lower buoyant bodies 7 provide buoyancy to the inner container 5 to maintain the opening 5 a of the inner container 5 at a position above the water surface when the pump 3 is not driven. As an example, the lower buoyant bodies 7 are solidly made of urethane.

A plurality of (three, for example) lower buoyant bodies 7 are detachably attached to the lower surface 54 of the inner container 5. The plurality of lower buoyant bodies 7 are preferably provided at equal or substantially equal angular intervals in the circumferential direction of the lower surface 54 of the annular inner container 5. Furthermore, the plurality of lower buoyant bodies 7 surround the water passage 53.

The plurality of lower buoyant bodies 7 each have an arcuate shape in which the inner peripheral surface 7 a and the outer peripheral surface 7 b extend along the annular lower surface 54 of the inner container 5, and have a plate shape with the upward-downward direction corresponding to its thickness direction. Thus, the plurality of lower buoyant bodies 7 each have a shape defined by two large and small arcs and two linear edges 7 c (see FIG. 2) connecting the two arcs as viewed in the upward-downward direction.

The lower buoyant bodies 7 are detachably attached to the lower surface 54 of the inner container 5 together with the stoppers 6. Specifically, the lower buoyant bodies 7 are detachably fixed to the lower surface 54 of the inner container 5 together with the stoppers 6 by the fasteners B. As an example, the fasteners B are bolts and nuts. Thus, the lower buoyant bodies 7, the stoppers 6, and the lower surface 54 of the inner container 5 are co-tightened by the fasteners B such as bolts and nuts, and are fixed to each other.

The lower buoyant bodies 7 each include recesses (counterbores) 70 (see FIG. 2) that are recessed upward such that the heads of the bolts, which are the fasteners B, do not protrude below the lower surfaces of the lower buoyant bodies 7.

The lower buoyant bodies 7 are replaceable with other lower buoyancy bodies 7 having different buoyancy magnitudes, and the buoyancy magnitudes are settable (adjustable) according to various conditions such as the usage environment of the marine debris collection device 100. The various conditions refer to various conditions that influence floating of the inner container 5 and the lower buoyant bodies 7 such as the water quality of seawater, the weight of the inner container 5, and the driving output of the pump 3.

The upper buoyant body 9 is provided on an upper portion of the inner container 5, and provides buoyancy to the inner container 5. The upper buoyant body 9 is located below the water surface when the pump 3 is driven, and holds the opening 5 a above the water surface when the pump 3 is not driven. The upper buoyant body 9 includes a sealed, hollow, and annular portion 9 a of the protrusion 55 b of the inner container 5.

Specifically, the upper buoyant body 9 includes the protrusion 55 b and a plate 90 attached to the lower side of the protrusion 55 b to seal the internal space of the protrusion 55 b. In short, the upper buoyant body 9 has a floating ring-shaped structure filled with air.

The plate 90 of the upper buoyant body 9 comes into contact with the upper surface 13 of the outer container 1 from above. In short, the plate 90 of the upper buoyancy body 9 defines a lowermost position in the movement range of the inner container 5 in the upward-downward direction.

The operation of the marine debris collection device 100 is now described in order with reference to FIGS. 1 and 3 to 5.

First, as shown in FIG. 1, when the pump 3 is not driven, the opening 5 a of the inner container 5 is located above the water surface. Then, as shown in FIG. 3, when the pump 3 starts to be driven, the water level in the inner container 5 drops. Consequently, the inner container 5 moves downward inside the outer container 1, and the opening 5 a and the upper surface 55 of the inner container 5 located above the water surface move to a height equal to or lower than the height of the water surface.

Consequently, as shown in FIG. 5, the seawater and debris G start to flow into the inner container 5 via the opening 5 a of the inner container 5. Specifically, the seawater passes over the protrusion 55 b of the upper surface 55 of the inner container 5 and flows inward of the inner container 5. Then, the seawater that has passed over the protrusion 55 b contacts the flat portion 55 a of the upper surface 55 of the inner container 5, and the flow is directed obliquely upward and inward. Thus, the seawater jumps inward of the inner container 5 at the flat portion 55 a. Consequently, the seawater and debris G are guided inward of the mesh container 51.

Then, the mesh container 51 allows the seawater that has flowed into the inner container 5 to pass therethrough toward the water passage 53, and the debris G is stored inside the mesh container 51.

Then, as shown in FIG. 4, the seawater that has passed through the mesh container 51 and the water passage 53 and from which the debris G has been removed flows into the pump 3 and then is divided into two branches by the branch discharge pipe 31 and discharged into the sea.

According to the first preferred embodiment of the present invention, the following advantageous effects are achieved.

According to the first preferred embodiment of the present invention, the marine debris collection device 100 includes the lower buoyant bodies 7 detachably attached to the lower portion of the inner container 5 that is movable in the upward-downward direction with respect to the outer container 1 to provide buoyancy to the inner container 5 and hold the opening 5 a above the water surface when the pump 3 is not driven. Accordingly, unlike the conventional structure in which the buoyancy of the inner container is determined by the shape of the inner container itself, which is a buoyant body, the buoyancy of the inner container 5 is determined by the lower buoyant bodies 7 different from the inner container 5 and detachably attached to the lower portion of the inner container 5. Therefore, the buoyancy of the inner container 5 is set by detaching and replacing the lower buoyant bodies 7 with other lower buoyant bodies 7 having different buoyancies, for example, without changing the shape of the inner container 5 itself. Therefore, the buoyancy of the inner container 5 is easily set by the lower buoyant bodies 7 attachable to and detachable from the inner container 5. Thus, the marine debris collection device 100 facilitates setting of the buoyancy of the inner container 5, and thus the buoyancy of the inner container 5 is easily set to preferred buoyancies depending on the area of the sea having various water qualities around the world. Therefore, the marine debris collection device 100 is used to collect the debris G on the sea and contribute to environmental conservation in the area of the sea having various water qualities around the world.

According to the first preferred embodiment of the present invention, the plurality of lower buoyant bodies 7 are detachably attached to the lower surface 54 of the inner container 5. Accordingly, as compared with a case in which one lower buoyant body 7 is attached, the overall buoyancy is easily fine-tuned by the plurality of lower buoyancy bodies 7.

According to the first preferred embodiment of the present invention, the inner container 5 includes the water passage 53 to allow the seawater to pass therethrough, and the plurality of lower buoyant bodies 7 surround the water passage 53. Accordingly, the lower buoyant bodies 7 are attached to the lower surface 54 of the inner container 5 without obstructing the flow of the seawater through the water passage 53.

According to the first preferred embodiment of the present invention, the lower surface 54 of the inner container 5 has an annular shape to surround the water passage 53, and the inner peripheral surfaces 7 a and the outer peripheral surfaces 7 b of the plurality of lower buoyant bodies 7 each have an arcuate shape to extend along the annular lower surface 54, and have a plate shape with the upward-downward direction corresponding to its thickness direction. Accordingly, the lower buoyant bodies 7 each have a shape along the lower surface 54 of the inner container 5, and thus a resistance of the lower buoyant bodies 7 to movement of the inner container 5 is significantly reduced or prevented when the inner container 5 moves in the upward-downward direction.

According to the first preferred embodiment of the present invention, the marine debris collection device 100 further includes the stoppers 6 attached to the inner container 5 to restrict upward movement of the inner container 5 at the predetermined height by contacting the outer container 1, and the lower buoyant bodies 7 are detachably attached to the lower surface 54 of the inner container 5 together with the stoppers 6. Accordingly, the lower buoyant bodies 7 and the stoppers 6 are attached together to the lower surface 54 of the inner container 5, and thus as compared with a case in which the lower buoyant bodies 7 and the stoppers 6 are attached to the lower surface 54 of the inner container 5 by different structures, the device structure is simplified.

According to the first preferred embodiment of the present invention, the marine debris collection device 100 further includes the fasteners B to detachably fix the lower buoyant bodies 7 together with the stoppers 6 to the lower surface 54 of the inner container 5. Accordingly, the lower buoyant bodies 7 and the stoppers 6 are easily attached to and detached from the inner container 5 by the fasteners B.

According to the first preferred embodiment of the present invention, the upper surface 55 of the inner container 5 includes the annular flat portion 55 a including the substantially horizontal surface and extending along the opening 5 a to surround the opening 5 a, and the annular protrusion 55 b surrounding the flat portion 55 a, protruding upward from the flat portion 55 a, and connected to the outer peripheral edge 55 c of the flat portion 55 a from above. Accordingly, the seawater and debris G in the vicinity of or adjacent to the water surface that have passed over the protrusion 55 b contact the flat portion 55 a such that the flow from the upper side to the lower side is directed inward horizontally, and obliquely upward and inward (i.e., the seawater is caused to jump obliquely upward and inward) in front of the opening 5 a. Consequently, a strong flow toward the vicinity of the center of the opening 5 a as a whole is generated inside the inner container 5, and thus the seawater and debris G are efficiently taken into the inner container 5.

According to the first preferred embodiment of the present invention, the protrusion 55 b preferably has an arcuate shape that protrudes upward in the direction perpendicular to the direction in which the protrusion 55 b annularly extends. Accordingly, the protrusion 55 b has an arcuate shape, and thus the seawater and debris G easily pass over the protrusion 55 b and flow into the inner container 5.

According to the first preferred embodiment of the present invention, the inner container 5 includes the cylindrical inner container body 50 and the mesh container 51 detachably installed inside the inner container body 50 to store the debris G and including the upper end 51 a located below the flat portion 55 a when the mesh container 51 is installed inside the inner container body 50, and the flat portion 55 a of the inner container 5 guides the seawater and debris G that flow over the protrusion 55 b into the inner container 5 inward of the mesh container 51 by contacting the inflowing seawater and debris G and directing the flow of the inflowing seawater and debris G obliquely upward and inward. Accordingly, the flow of the seawater and debris G that flow over the protrusion 55 b into the inner container 5 is directed obliquely upward and inward by the flat portion 55 a such that the seawater and debris G are guided to a location farther away from the upper end 51 a of the mesh container 51. Consequently, clogging of the space between the mesh container 51 and the inner container body 50 due to flowing of the debris G into between the mesh container 51 and the inner container body 50 is significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the mesh container 51 includes the removable handle 51 b. Accordingly, the handle 51 b is attached to the mesh container 51 such that the mesh container 51 is easily lifted. Furthermore, the handle 51 b is removed from the mesh container 51 such that the handle 51 b is prevented from obstructing the flow of the seawater flowing into the mesh container 51.

According to the first preferred embodiment of the present invention, the marine debris collection device 100 further includes the sliders 4 a provided between the outer container 1 and the inner container 5 to smooth the movement of the inner container 5 with respect to the outer container 1. Accordingly, when the inner container 5 moves in the upward-downward direction, the sliders 4 a reduce a resistance between the inner container 5 and the outer container 1.

According to the first preferred embodiment of the present invention, the marine debris collection device 100 further includes the seal 4 b provided in at least one of a location above or a location below the sliders 4 a and between the outer container 1 and the inner container 5 to prevent water from entering between the outer container 1 and the inner container 5. Accordingly, the seal 4 b prevents the seawater and debris G from flowing into between the outer container 1 and the inner container 5. Consequently, clogging of the space between the outer container 1 and the inner container 5 with the debris G is significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the marine debris collection device 100 further includes the upper buoyant body 9 that is provided on the upper portion of the inner container 5 to provide buoyancy to the inner container 5, is located below the water surface when the pump 3 is driven, and holds the opening 5 a above the water surface when the pump 3 is not driven. Accordingly, when the pump 3 is driven, the buoyancy of the upper buoyant body 9 is generated only when the upper portion of the inner container 5 is located below the water surface, and thus the upper portion of the inner container 5 is held below the water surface and in the vicinity of or adjacent to the water surface. Consequently, flowing of not only the seawater and debris G in the vicinity of or adjacent to the water surface but also seawater below in the vicinity of or adjacent to the water surface into the inner container 5 due to excessive movement of the upper portion of the inner container 5 below the water surface is significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the inner container 5 includes the annular flat portion 55 a that includes the substantially horizontal surface and extends along the opening 5 a to surround the opening 5 a, and the sealed, hollow, and annular protrusion 55 b that surrounds the flat portion 55 a, protrudes upward from the flat portion 55 a, and is connected to the outer peripheral edge 55 c of the flat portion 55 a from above, and the upper buoyant body 9 includes the sealed, hollow, and annular portion 9 a of the protrusion 55 b. Accordingly, the shape of the upper buoyant body 9 is determined by the shape of the hollow and annular portion 9 a of the protrusion 55 b of the inner container 5, and thus the device structure is simplified.

According to the first preferred embodiment of the present invention, the pump 3 is directly attached to the lower surface 12 of the outer container 1 from the outside of the outer container 1. Accordingly, the pump 3 is provided outside the outer container 1, and thus it is not necessary to provide a space to provide the pump 3 inside the outer container 1, and the outer container 1 is downsized.

According to the first preferred embodiment of the present invention, the inner container 5 includes the water passage 53 to allow the seawater to pass therethrough, and the pump 3 is provided outside the outer container 1 and directly below the water passage 53. Accordingly, the pump 3 is provided directly below the water passage 53, and thus the seawater that has passed through the water passage 53 is immediately suctioned by the pump 3. Therefore, the water is efficiently discharged by the pump 3.

According to the first preferred embodiment of the present invention, the pump 3 includes the pump body 30 and the branch discharge pipe 31 to divide the seawater discharged from the pump body 30 into the plurality of branches and discharge the seawater in the plurality of horizontal directions different from each other. Accordingly, the seawater discharged from the pump 3 is divided into a plurality of small flows and discharged by the branch discharge pipe 31, and thus disturbance of the flow of the seawater in the vicinity of or adjacent to the water surface due to the flow of the seawater discharged from the pump 3 is significantly reduced or prevented. Furthermore, the branch discharge pipe 31 cancels a reaction force received by the pump 3 (marine debris collection device 100) from the flow of the seawater discharged from the pump 3.

According to the first preferred embodiment of the present invention, the lower buoyant bodies 7 are preferably solid. Accordingly, the solid lower buoyant bodies 7 facilitate setting of the buoyancy of the inner container 5.

According to the first preferred embodiment of the present invention, the marine debris collection device 100 further includes the bracket 2 to fix the outer container 1 to the pier F. Accordingly, the outer container 1 is easily fixed to the pier F by the bracket 2.

According to the first preferred embodiment of the present invention, the plurality of lower buoyant bodies 7 are provided at the equal or substantially equal angular intervals in the circumferential direction of the lower surface 54 of the annular inner container 5. Accordingly, the plurality of lower buoyant bodies 7 are provided in a balanced manner with respect to the inner container 5, and thus the plurality of lower buoyant bodies 7 provide buoyancy to the inner container 5 in a balanced manner.

Second Preferred Embodiment

A second preferred embodiment of the present invention is now described with reference to FIGS. 6 to 13. In the second preferred embodiment, a lower portion of a protrusion 255 b of an inner container 205 is open, unlike the first preferred embodiment in which the protrusion 55 b of the inner container 5 is hollow and enclosed. In the figures, the same or similar structures as those of the first preferred embodiment are denoted by the same reference numerals.

A marine debris collection device 200 according to the second preferred embodiment shown in FIGS. 6 and 7 includes a bracket 202, a pump 203, the inner container 205 including an inner container body 250 and a mesh container 51, and lower buoyant bodies 207 (see FIG. 7), and a self-supporting stand S.

As shown in FIG. 7, the inner container 205 (inner container body 250) includes the protrusion 255 b, a water-impermeable portion 256, and water passages 257 to allow seawater to pass therethrough. The water passages 257 include bottom water passages 257 a provided on the bottom surface 205 a of the inner container and side water passages 257 b provided on the side surface 205 b of the inner container 205.

The protrusion 255 b is provided at the upper end of the inner container body 250 to surround an opening 5 a of the inner container body 250. Thus, the protrusion 255 b has an annular shape.

As shown in FIG. 8, the protrusion 255 b is internally recessed upward such that the lower side of the protrusion 255 b is open. Thus, the protrusion 255 b has a concave shape in a sectional view. The protrusion 255 b is located in the atmosphere above the water surface when the pump 203 (see FIG. 7) is not driven. Therefore, the internal space I of the protrusion 255 b is filled with air when the pump 203 is not driven.

The protrusion 255 b includes a plurality of through-holes TH on its outer surface. The through-holes TH are provided on the inner peripheral side of the top T (a broken line in FIG. 8) of the outer surface that is annularly continuous at a height lower than the height of the top T. The plurality of through-holes TH are spaced apart from each other at predetermined angular intervals in the circumferential direction of the annular protrusion 255 b. As an example, eighteen through-holes TH are provided at an angular interval of about 20 degrees. Furthermore, as an example, the through-holes TH each have a circular shape having a diameter of about 3 mm.

When the pump 203 is driven and seawater flows into the inner container 205, air inside the protrusion 255 b is drawn via the through-holes TH into the seawater that flows into the inner container 205, and the seawater flows into the protrusion 255 b from the open lower side. Therefore, in the internal space I of the protrusion 255 b, the water level gradually rises while the amount of air gradually decreases. Thus, the protrusion 255 b is gradually submerged. When air in the internal space I of the protrusion 255 b reaches a predetermined amount, the height of the protrusion 255 b (inner container 205) with respect to the water surface is substantially determined.

As shown in FIG. 1, the inner container 5 according to the first preferred embodiment includes the upper buoyant body 9, but the inner container 205 according to the second preferred embodiment does not include an upper buoyant body, as shown in FIG. 7. Thus, the marine debris collection device 100 according to the first preferred embodiment includes two types of buoyant bodies: the upper buoyant body 9 and the lower buoyant bodies 7, whereas the marine debris collection device 200 according to the second preferred embodiment includes only the lower buoyant bodies 207.

Therefore, the lower buoyant bodies 207 according to the second preferred embodiment each have a larger thickness in an upward-downward direction (Z direction) than the lower buoyant bodies 7 according to the first preferred embodiment so as to generate a larger buoyancy.

A suction port 203 a of the pump 203 is provided directly below a substantially central portion of the bottom surface 205 a of the inner container 205.

The water-impermeable portion 256 is provided on the bottom surface 205 a directly above the suction port 203 a to prevent seawater from passing therethrough. The bottom water passages 257 a are provided on the bottom surface 205 a around the water-impermeable portion 256.

As shown in FIGS. 9 and 10, the water-impermeable portion 256 has a circular flat plate shape to extend in a horizontal direction with the upward-downward direction corresponding to its thickness direction. The water-impermeable portion 256 is substantially surrounded by the circular bottom water passages 257 a. The water-impermeable portion 256 is preferably integral and unitary with the inner container body 250. Thus, the water-impermeable portion 256 is integrally connected to the inner container body 250 via a plurality of connections 256 a that radially extend from the water-impermeable portion 256.

As shown in FIG. 10, the water-impermeable portion 256 blocks (obstructs) the flow of the seawater such that the seawater containing the air that has flowed into the inner container 205 does not directly flow into the suction port 203 a. Thus, the water-impermeable portion 256 separates the air contained in the seawater and decreases the amount of air that flows into the suction port 203 a by blocking the flow of the seawater containing the air that has flowed into the inner container 205. Consequently, the amount of air suctioned into the pump 203 decreases, and a decrease in the efficiency of water discharge of the pump 203 due to air suction is significantly reduced or prevented.

A plurality of side water passages 257 b are provided on the cylindrical (annular) side surface 205 b of the inner container body 250. The plurality of side water passages 257 b are spaced apart from each other at predetermined angular intervals around the bottom water passages 257 a. As an example, six side water passages 257 b are provided at an angular interval of about 60 degrees.

The side water passages 257 b are provided in the vicinity of or adjacent to the bottom surface 205 a in the upward-downward direction. The side water passages 257 b each have an oval shape (or an elliptical shape) with the horizontal direction corresponding to its longitudinal direction. In the horizontal direction, a distance L20 between the side water passages 257 b adjacent to each other is smaller than the size L21 of each of the side water passages 257 b (see FIG. 9).

The side water passages 257 b are provided on the side surface 205 b of the inner container body 250, and thus they are less likely to be blocked by debris (less likely to be clogged with debris) as compared with the bottom water passages 257 a. Therefore, the side water passages 257 b continue to allow the seawater to pass therethrough toward the pump 203 even when the bottom water passages 257 a are blocked by debris (such as plastic bags).

As shown in FIG. 7, the pump 203 includes a pump body 30 and an outer discharge pipe 231 including a discharge port 231 a.

The discharge port 231 a is provided outside the outer peripheral surface 14 of an outer container 1 in the horizontal direction. Thus, the pump 203 discharges the seawater around the outer container 1 instead of discharging the seawater directly under the outer container 1. As an example, a distance L1 from the discharge port 231 a of the pump 203 to the outer peripheral surface 14 of the outer container 1 is at least about 50 centimeters in the horizontal direction.

The outer discharge pipe 231 discharges the seawater discharged from the pump body 30 to the outside via the discharge port 231 a. The outer discharge pipe 231 extends linearly in the horizontal direction opposite to the bracket 202 and a pier F. Thus, the outer discharge pipe 231 is a cylindrical pipe that extends linearly. Therefore, the outer discharge pipe 231 discharges the seawater into the sea at substantially the same height as the pump body 30.

As shown in FIG. 11, when the marine debris collection device 200 is transported by land with a wheel assembly W of the bracket 202 described below, the marine debris collection device 200 is held by a user while the bracket 202 side (the C2 direction side described below) is lower than the outer container 1. Therefore, when the marine debris collection device 200 is transported by land, the outer discharge pipe 231 is held while extending obliquely upward such that the discharge port 231 a is located above the pump body 30. Thus, the outer discharge pipe 231 is held so as to not contact the ground.

The bracket 202 shown in FIGS. 12 and 13 fixes a marine debris collection device body 200 a to the pier F and assists in the movement of the marine debris collection device body 200 a on land. The “marine debris collection device body 200 a” refers to the marine debris collection device 200 from which the bracket 202 has been removed.

The bracket 202 includes a support bracket 202 a, a handle H, the wheel assembly W for land transportation, and a fixing bracket 202 b directly attached to the pier F.

The support bracket 202 a includes a support 20 that directly supports the outer container 1, a rod 21 that extends linearly in the upward-downward direction, and a mount 22 attached to the fixing bracket 202 b.

The support 20 is fixed in the vicinity of or adjacent to the lower end of the rod 21. The rod 21 extends in the upward-downward direction with the marine debris collection device body 200 a being installed in the water. With the marine debris collection device body 200 a being installed in the water, the upper end of the rod 21 is located above the outer container 1, and the lower end of the rod 21 is located below the outer container 1. As an example, the rod 21 is a quadrangular prism-shaped member.

In FIGS. 6, 7, and 11 to 13, a direction in which the rod 21 and the outer container 1 are aligned is indicated by a C direction, a direction from the rod 21 toward the outer container 1 in the C direction is indicated by a C1 direction, and a direction opposite to the C1 direction is indicated by a C2 direction.

In FIGS. 6, 7, and 11 to 13, a direction perpendicular to both the C direction and a direction in which the rod 21 extends is indicated by a D direction.

As shown in FIGS. 12 and 13, the mount 22 is provided on the rod 21. The mount 22 is fixed to the rod 21. With the marine debris collection device body 200 a being installed in the water, the mount 22 is located on the upper side of the rod 21 and above the outer container 1. The mount 22 is detachably attached to the fixing bracket 202 b by fasteners B1 such as bolts.

The mount 22 is attached to the fixing bracket 202 b by the fasteners B1 when the marine debris collection device body 200 a is moved from land into water and installed. The mount 22 is detached from the fixing bracket 202 b when the marine debris collection device body 200 a is moved from the water onto land.

The handle H is provided on the rod 21. The handle H is provided above the mount 22. The handle H is gripped by the user when the marine debris collection device body 200 a is moved, for example.

The wheel assembly W for land transportation is installed at the lower end of the support bracket 202 a. The wheel assembly W is provided below the outer container 1. The wheel assembly W includes a pair of wheels W1 spaced apart from each other in the D direction (see FIG. 6). The wheel assembly W is provided on the C2 direction side relative to the pump 203.

The wheel assembly W is located below the pier F with the marine debris collection device body 200 a being installed in the water. Therefore, the wheel assembly W does not interfere with the pier F.

The fixing bracket 202 b is directly attached to the pier F by fasteners B2 such as bolts. Specifically, the fixing bracket 202 b is directly attached to a corner of the pier F adjacent to the sea surface. The support bracket 202 a is attached to the fixing bracket 202 b attached to the pier F such that the fixing bracket 202 b fixes the outer container 1 to the pier F.

A mobility aid roller R is provided at the upper end of the fixing bracket 202 b. The mobility aid roller R is rotatable about a central axis a (see FIG. 12) that extends in the D direction.

When the outer container 1 (marine debris collection device body 200 a) is moved between land and water, the mobility aid roller R assists in the movement of the outer container 1 (marine debris collection device body 200 a) by contacting the rod 21 of the support bracket 202 a and guiding the movement of the support bracket 202 a. A central portion of the mobility aid roller R is thinner than both ends of the mobility aid roller R in the D direction such that the contact state of the rod 21 is stable.

The size L10 (see FIG. 12) of the mobility aid roller R in the D direction is smaller than a separation distance L11 (see FIG. 6) between the pair of wheels W1 of the wheel assembly W. Furthermore, the mobility aid roller R protrudes a predetermined amount from the upper end of the fixing bracket 202 b to not interfere with the pair of wheels W1. Thus, the marine debris collection device 200 interposes the mobility aid roller R between the pair of wheels W1 of the wheel assembly W and straddles the mobility aid roller R when the wheel assembly W passes in the vicinity of the mobility aid roller R.

The self-supporting stand S shown in FIG. 6 allows the marine debris collection device body 200 a to stand by itself on land. The marine debris collection device body 200 a is held in substantially the same direction as the marine debris collection device body 200 a installed in the water when standing by itself with the self-supporting stand S. The self-supporting stand S extends downward from the lower end of the outer container 1. As an example, the self-supporting stand S is a U-shaped member that extends downward from the lower end of the outer container 1.

The self-supporting stand S is located on the side (C1 direction side) opposite to the wheel assembly W with respect to the pump 203 in the horizontal direction when allowing the marine debris collection device body 200 a to stand by itself. Therefore, the pump 203 is located between the wheel assembly W and the self-supporting stand S, both of which contact the ground, when the marine debris collection device body 200 a stands by itself with the self-supporting stand S, and thus the pump 203 does not contact the ground.

According to the second preferred embodiment of the present invention, the following advantageous effects are achieved.

According to the second preferred embodiment of the present invention, the marine debris collection device 200 includes the lower buoyant bodies 207 detachably attached to a lower portion of the inner container 205 that is movable in the upward-downward direction with respect to the outer container to provide buoyancy to the inner container 205 and hold the opening 5 a above the water surface when the pump 203 is not driven. Accordingly, similarly to the first preferred embodiment, the buoyancy of the inner container 205 is easily set by the lower buoyant bodies 207 attachable to and detachable from the inner container 205.

According to the second preferred embodiment of the present invention, the protrusion 255 b is internally recessed upward such that the lower side of the protrusion 255 b is open, and includes the outer surface including the through-holes TH. When seawater flows into the inner container 205, the internal air is drawn via the through-holes TH into the seawater that flows into the inner container 205, and the seawater flows into the protrusion 255 b from the open lower side. Accordingly, the air inside the protrusion 255 b is allowed to flow into the inner container 205 via the through-holes TH by the flow of the seawater, and the seawater is allowed to flow into the protrusion 255 b from the open lower side of the protrusion 255 b. Thus, the inner container 205 is submerged such that the position of the protrusion 255 b with respect to the water surface is lower. Consequently, the protrusion 255 b is located at a lower position with respect to the water surface, and thus the flow of the seawater that flows into the inner container 205 is further increased, and the debris G is effectively attracted.

According to the second preferred embodiment of the present invention, the bracket 202 includes the wheel assembly W for land transportation provided below the outer container 1. Accordingly, when the outer container 1 (marine debris collection device body 200 a) is pulled up to land, the outer container 1 (marine debris collection device body 200 a) is easily moved by the wheel assembly W.

According to the second preferred embodiment of the present invention, the marine debris collection device 200 further includes the self-supporting stand S to allow the marine debris collection device body 200 a to stand by itself on land, and the self-supporting stand S is located on the side opposite to the wheel assembly W with respect to the pump 203 in the horizontal direction when allowing the marine debris collection device body 200 a to stand by itself. Accordingly, by the self-supporting stand S, the marine debris collection device body 200 a is allowed to easily stand by itself on land with the pump 203 being located between the self-supporting stand S and the wheel assembly W.

According to the second preferred embodiment of the present invention, the bracket 202 includes the support bracket 202 a to support the outer container 1 and the fixing bracket 202 b attached to the pier F to allow the support bracket 202 a to be attached to the fixing bracket 202 b attached to the pier F so as to fix the outer container 1 to the pier F, and the fixing bracket 202 b includes the mobility aid roller R to assist in the movement of the outer container 1 by contacting the support bracket 202 a and guiding the movement of the support bracket 202 a when the outer container 1 is moved between land and water. Accordingly, when the outer container 1 is moved between land and water, the mobility aid roller R assists in the movement of the outer container 1, and thus the outer container 1 is easily moved between land and water.

According to the second preferred embodiment of the present invention, the pump 203 includes the suction port 203 a provided directly below the substantially central portion of the bottom surface 205 a of the inner container 205, and the inner container 205 includes the water-impermeable portion 256 provided on the bottom surface 205 a directly above the suction port 203 a to prevent seawater from passing therethrough, and the bottom water passages 257 a provided on the bottom surface 205 a around the water-impermeable portion 256 to allow seawater to pass therethrough. Accordingly, the water-impermeable portion 256 significantly reduces or prevents the possibility that air directly enters the pump 203, and thus the seawater is allowed to more efficiently flow into the pump 203. Consequently, the efficiency of water discharge of the pump 203 is improved.

According to the second preferred embodiment of the present invention, the inner container 205 includes the water passages 257 to allow seawater to pass therethrough, and the water passages 257 include the bottom water passages 257 a provided on the bottom surface 205 a of the inner container 205 and the side water passages 257 b provided on the side surface 205 b of the inner container 205. Accordingly, the debris G gradually accumulates from below inside the inner container 205, and thus even when the bottom water passages 257 a in which the debris G is likely to accumulate (i.e., that are likely to be clogged with the debris G) is clogged, the debris G is continuously collected by the side water passages 257 b in which the debris G is unlikely to accumulate (i.e., that are unlikely to be clogged with the debris G). Consequently, the marine debris collection device 200 continues to collect the debris G for a relatively long time. Therefore, the maintenance interval to remove the debris G from the marine debris collection device 200 is lengthened.

According to the second preferred embodiment of the present invention, the pump 203 includes the pump body 30 and the outer discharge pipe 231 including the discharge port 231 a provided outside the outer peripheral surface 14 of the outer container 1 in the horizontal direction to discharge the seawater discharged from the pump body 30 to the outside via the discharge port 231 a. Accordingly, the outer discharge pipe 231 discharges the seawater and the air (air bubbles) contained in the seawater into the sea at a location relatively far from the outer container 1, and thus generation of air bubbles in the vicinity of or adjacent to the outer container 1 is significantly reduced or prevented. Consequently, obstruction of the flow of the debris G into the inner container 205 due to generated air bubbles is significantly reduced or prevented.

According to the second preferred embodiment of the present invention, the through-holes TH are provided on the inner peripheral side of the outer surface of the protrusion 255 b. Accordingly, the through-holes TH are provided on the inner peripheral side of the outer surface of the protrusion 255 b on which the flow of the seawater that flows into the inner container 205 becomes particularly fast, and thus the air inside the protrusion 255 b is allowed to more effectively flow into the inner container 205 via the through-holes TH. Consequently, a lower portion of the protrusion 255 b is more easily positioned in the water to attract the debris G more effectively.

According to the second preferred embodiment of the present invention, the plurality of side water passages 257 b are provided around the bottom water passages 257 a at the predetermined angular intervals. Accordingly, the plurality of side water passages 257 b allow the seawater to flow toward the pump 203 in a balanced manner such that the debris G is effectively collected.

According to the second preferred embodiment of the present invention, the marine debris collection device 200 further includes the bracket 202 to fix the outer container 1 to the pier F floating on the water surface, and the outer discharge pipe 231 extends in the horizontal direction opposite to the bracket 202. Accordingly, obstruction of the flow of the air bubbles by the pier F and the bracket 202 due to movement of air bubbles discharged from the pump 203 toward the pier F and the bracket 202, which are relatively close to the outer container 1, is prevented. Consequently, generation of air bubbles in the vicinity of or adjacent to the outer container 1 is significantly reduced or prevented.

The remaining advantageous effects of the second preferred embodiment are similar to those of the first preferred embodiment.

The preferred embodiments of the present invention described above are illustrative in all points and not restrictive. The extent of the present invention is not defined by the above description of the preferred embodiments but by the scope of the claims, and all modifications within the meaning and range equivalent to the scope of the claims are further included.

For example, while the marine debris collection device preferably includes both the lower and upper buoyant bodies in the first preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the marine debris collection device may alternatively include the lower buoyant bodies but may not include the upper buoyant body.

While the marine debris collection device preferably includes the three lower buoyant bodies in each of the first and second preferred embodiments described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, as in a modified example shown in FIG. 14, a marine debris collection device 300 may alternatively include only one annular lower buoyant body 307. One lower buoyant body may alternatively have an arcuate shape (C shape) instead of an annular shape. Furthermore, the marine debris collection device may alternatively include two or four or more lower buoyant bodies.

While the lower buoyant bodies are preferably attached to the lower surface of the lower portion of the inner container in each of the first and second preferred embodiments described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the lower buoyant bodies may alternatively be attached to the side surface of the lower portion of the inner container. Similarly, the upper buoyant body may alternatively be attached to the side surface of the outer container. In addition, similarly to the lower buoyant bodies, the upper buoyant body may alternatively be attachable to and detachable from the outer container.

While the marine debris collection device is preferably installed on the pier floating on the water surface in each of the first and second preferred embodiments described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the marine debris collection device may alternatively be installed on any structure such as a marine vessel, a quay, a pier fixed to a quay or the like, or a pontoon as long as the same is placed in the vicinity of or adjacent to the water surface to be activated. Furthermore, a floating body dedicated to the marine debris collection device may alternatively be provided on the water surface in order to install the marine debris collection device.

While bolts and nuts are preferably used as the fasteners to attach the lower buoyant bodies to the inner container in each of the first and second preferred embodiments described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, for example, the inner container and the lower buoyant bodies may alternatively be sandwiched by a sandwiching member such that the lower buoyant bodies are attached to the inner container.

While the lower buoyant bodies are preferably solid in each of the first and second preferred embodiments described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the lower buoyant bodies may alternatively be hollow.

While the upper buoyant body is preferably hollow in the first preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the upper buoyant body may alternatively be solid.

While the seawater is preferably discharged in the horizontal direction by the pump in each of the first and second preferred embodiments described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the seawater may alternatively be discharged in a direction different from the horizontal direction such as a downward direction by the pump.

While the seawater is preferably divided into two branches by the branch discharge pipe of the pump and discharged into the sea in the first preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the seawater may alternatively be divided into three or more branches by the branch discharge pipe of the pump and discharged into the sea. Furthermore, the seawater may alternatively be discharged into the sea without being divided into branches by the pump.

While the protrusion preferably has an arcuate shape that protrudes upward in the direction perpendicular to the direction in which the protrusion annularly extends in the first preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, as in a first modified example shown in FIG. 15, a protrusion 355 b may alternatively have a triangular shape in which the outer peripheral side is higher in a direction perpendicular to a direction in which the protrusion 355 b annularly extends. In addition, as in a second modified example shown in FIG. 16, a protrusion 455 b may alternatively have a flat plate shape in which the outer peripheral side is higher in a direction perpendicular to a direction in which the protrusion 455 b annularly extends.

In a preferred embodiment of the present invention, the shapes of the lower buoyant bodies are not restricted to the shapes shown in the first and second preferred embodiments. In a preferred embodiment of the present invention, the lower buoyant bodies may alternatively have various shapes such as a rectangular parallelepiped shape, a cylindrical shape, and a polygonal pillar shape.

While the handle is preferably removable from the mesh container in each of the first and second preferred embodiments described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the handle may alternatively be fixed to be unremovable from the mesh container.

While the water-impermeable portion is preferably integral and unitary with the inner container body in the second preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the water-impermeable portion may alternatively be separate from the inner container body. In such a case, the water-impermeable portion may alternatively be provided in the mesh container.

While the six side water passages are preferably provided in the inner container in the second preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, five or less or seven or more side water passages may alternatively be provided in the inner container.

While each of the side water passages preferably has an oval shape (or an elliptical shape) in the second preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, each of the side water passages may alternatively have a circular shape or a polygonal shape, for example.

While the through-holes are preferably provided on the inner peripheral side of the outer surface of the protrusion in the second preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, the through-holes may alternatively be provided on the outer peripheral side of the outer surface of the protrusion.

While the eighteen through-holes are preferably provided in the protrusion in the second preferred embodiment described above, the present invention is not restricted to this. In a preferred embodiment of the present invention, seventeen or less or nineteen or more through-holes may alternatively be provided in the protrusion.

While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims. 

What is claimed is:
 1. A marine debris collection device that collects debris floating on a sea by allowing the debris to flow together with seawater into the marine debris collection device, the marine debris collection device comprising: an outer container installed in a vicinity of or adjacent to a water surface to maintain a height of the outer container; an inner container including, in an upper portion thereof, an opening to allow the seawater and the debris to flow into the inner container, the inner container being provided inside the outer container so as to be movable in an upward-downward direction with respect to the outer container to store the debris that flows into the inner container via the opening; a pump driven to move the inner container downward such that the opening is located at a height equal to or lower than a height of the water surface and cause the seawater and the debris to flow into the inner container via the opening; and a lower buoyant body detachably attached to a lower portion of the inner container to provide buoyancy to the inner container so as to maintain the opening above the water surface when the pump is not driven.
 2. The marine debris collection device according to claim 1, wherein the lower buoyant body includes a plurality of lower buoyant bodies detachably attached to a lower surface of the inner container.
 3. The marine debris collection device according to claim 2, wherein the inner container includes a water passage to allow the seawater to pass therethrough; and the plurality of lower buoyant bodies surround the water passage.
 4. The marine debris collection device according to claim 3, wherein the lower surface of the inner container has an annular shape to surround the water passage; and each of the plurality of lower buoyant bodies includes an inner peripheral surface and an outer peripheral surface each having an arcuate shape extending along the lower surface and having a plate shape with the upward-downward direction corresponding to a thickness direction of the plate shape.
 5. The marine debris collection device according to claim 1, further comprising: a stopper attached to the inner container to restrict upward movement of the inner container at a predetermined height by contacting the outer container; wherein the lower buoyant body is detachably attached to a lower surface of the inner container together with the stopper.
 6. The marine debris collection device according to claim 5, further comprising: a fastener to detachably fix the lower buoyant body together with the stopper to the lower surface of the inner container.
 7. The marine debris collection device according to claim 1, wherein the inner container includes an upper surface including: an annular flat portion that includes a horizontal or substantially horizontal surface and extends along the opening to surround the opening; and an annular protrusion that surrounds the flat portion, protrudes upward from the flat portion, and is connected to an outer peripheral edge of the flat portion from above.
 8. The marine debris collection device according to claim 7, wherein the protrusion has an arcuate shape that protrudes upward in a direction perpendicular to a direction in which the protrusion extends around the opening.
 9. The marine debris collection device according to claim 7, wherein the inner container includes: a cylindrical inner container body; and a mesh container detachably installed inside the cylindrical inner container body to store the debris and including an upper end located below the flat portion when the mesh container is installed inside the inner container body; and the flat portion of the inner container guides, inward of the mesh container, the seawater and the debris that flow over the protrusion into the inner container by contacting the seawater and debris flowing inward and directing a flow of the seawater and debris obliquely upward and inward.
 10. The marine debris collection device according to claim 7, wherein the protrusion is internally recessed upward such that a lower side of the protrusion is open, and includes an outer surface including a through-hole; and when the seawater flows into the inner container, internal air is drawn via the through-hole into the seawater that flows into the inner container, and the seawater flows into the protrusion from the open lower side.
 11. The marine debris collection device according to claim 1, further comprising: a slider provided between the outer container and the inner container to smooth a movement of the inner container with respect to the outer container.
 12. The marine debris collection device according to claim 1, further comprising: an upper buoyant body that is provided on the upper portion of the inner container to provide buoyancy to the inner container, is located below the water surface when the pump is driven, and maintains the opening above the water surface when the pump is not driven.
 13. The marine debris collection device according to claim 12, wherein the inner container includes: an annular flat portion that includes a horizontal or substantially horizontal surface and extends along the opening to surround the opening; and a sealed, hollow, and annular protrusion that surrounds the flat portion, protrudes upward from the flat portion, and is connected to an outer peripheral edge of the flat portion from above; and the upper buoyant body includes a sealed, hollow, and annular portion of the protrusion.
 14. The marine debris collection device according to claim 1, wherein the pump is directly attached to a lower surface of the outer container from an outside of the outer container.
 15. The marine debris collection device according to claim 1, wherein the pump includes: a pump body; and a branch discharge pipe to divide the seawater discharged from the pump body into a plurality of branches and discharge the seawater in a plurality of horizontal directions different from each other.
 16. The marine debris collection device according to claim 1, wherein the lower buoyant body is solid.
 17. The marine debris collection device according to claim 1, further comprising: a bracket to fix the outer container to a pier.
 18. The marine debris collection device according to claim 1, wherein the pump includes a suction port provided directly below a central or substantially central portion of a bottom surface of the inner container; and the inner container includes: a water-impermeable portion provided on the bottom surface directly above the suction port to prevent the seawater from passing therethrough; and a bottom water passage provided on the bottom surface around the water-impermeable portion to allow the seawater to pass therethrough.
 19. The marine debris collection device according to claim 1, wherein the inner container includes a water passage to allow the seawater to pass therethrough; and the water passage includes: a bottom water passage provided on a bottom surface of the inner container; and a side water passage provided on a side surface of the inner container.
 20. The marine debris collection device according to claim 1, wherein the pump includes: a pump body; and an outer discharge pipe including a discharge port provided outside an outer peripheral surface of the outer container in a horizontal direction to discharge the seawater discharged from the pump body to an outside of the pump via the discharge port. 